Isolated efforts, small sample sizes and interventions with limited duration hamper research on quality improvement for drug abuse treatment. An initiative that includes nearly 50 drug abuse treatment programs provides an opportunity to examine the longitudinal application of process improvement and to assess organizational ability to sustain process improvements. The Robert Wood Johnson Foundation's Paths to Recovery (Paths) and the Center for Substance Abuse Treatment's Strengthening Treatment Access and Retention (STAR) are coordinated initiatives using process improvement strategies to enhance access to care and improve retention in care. This proposal addresses a major issue-sustainability and generalization of process improvement after program participation is finished. Participating sites will continue to report access and retention data for 18 months and continue to participate in quarterly interviews and site visits. A validated model of organizational change (the Organizational Change Manager) guides the analysis. The specific aim (i.e., Assess stability of change, record generalization beyond the initial focus on access and retention, and identify organizational factors that contribute to sutainability and generalization during an 18 month period following termination of program support) tests 3 hypotheses: H1: Gains achieved during the project (reduced days to admission, increased admissions, improved continuation, and reduced no-shows) will be maintained at a stable plateau during 18 months of follow-up. H2: The use of process improvement will continue and generalize to other treatment units within the organization and to other treatment processes within the participating center. H3: Six OCM dimensions (change leader is strong, executive leadership is involved, staff support change, external ideas, environment is supportive, and tension for change) will be associated with a greater likelihood of sustained use of process improvement and sustained gains in access and retention.